1. Field of the Invention
This invention relates to new oxoindolizine and oxoindolizinium dyes. It also relates to the preparation of such dyes.
2. Description of the State of the Art
Dyes useful in imaging materials are well known in the photographic art. However, a continuing need has existed for new classes of dyes having a wide absorption range and which are prepared without the need for complex multistep reactions.
Attempts have been made to react cyclopropenones with heteroaromatic nitrogen compounds as described in, for example, "Reaction of Cyclopropenones With Heterocyclic Nitrogen Compounds" by J. W. Lown and K. Matsumoto, Canadian Journal of Chemistry, Vol. 49, 1971, pages 1165-1175. However, such attempts did not produce an oxoindolizine or oxoindolizinium dye. None of the classes of dyes have involved preparation by means of a simple reaction of a cyclopropenone with a pyridine compound. Also, none of the classes of dyes have involved reaction of (1) color-forming couplers with (2) reaction products from reaction of photosensitive cyclopropenones with pyridine compounds. In addition, none of the classes of dyes have involved color-forming condensation reactions of the reaction products of cyclopropenones and pyridine compounds.